Bicyclic [4,6,0] hydroxamic acids as hdac inhibitors

ABSTRACT

The present invention relates to inhibitors of zinc-dependent histone deacetylases (HDACs) useful in the treatment of diseases or disorders associated with HDAC6, having a Formulae I or Formula II: 
     
       
         
         
             
             
         
       
     
     where R, L, X 1 , X 2 , X 3 , X 4 , X 5 , Y 1 , Y 2 , Y 3 , and Y 4  are described herein.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority of U.S. ProvisionalApplication No. 62/110,719, filed Feb. 2, 2015, the contents of which ishereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to inhibitors of zinc-dependent histonedeacetylases (HDACs) useful in the treatment of diseases or disordersassociated with HDACs including cell proliferation diseases (e.g.,cancer), neurological and inflammatory diseases. Specifically, thisinvention is concerned with compounds and compositions inhibiting HDACs,methods of treating diseases associated with HDACs, and methods ofsynthesizing these compounds.

BACKGROUND OF THE INVENTION

Many members of the HDAC family require zinc (Zn) to function properly.For instance, the isozyme histone deacetylase 6 (HDAC6) is azinc-dependent histone deacetylase that possesses histone deacetylaseactivity. Other family members include HDACs 1-5 and 7-11. (De Ruijteret al, Biochem. J. 2003. 370; 737-749).

HDAC6 is known to deacetylate and associate with α-tubulin, cortactin,heat shock protein 90, ß-catenin, glucose-regulated protein 78 kDa,myosin heavy chain 9, heat shock cognate protein 70, and dnaJ homologsubfamily A member 1 (reviewed in Li et al, FEBS J. 2013, 280: 775-93;Zhang et al, Protein Cell. 2015, 6(1): 42-54). Diseases in which HDAC6inhibition could have a potential benefit include cancer (reviewed inAldana-Masangkay et al, J. Biomed. Biotechnol. 2011, 875824),specifically: multiple myeloma (Hideshima et al, Proc. Natl. Acad. SciUSA 2005, 102(24):8567-8572); lung cancer (Kamemura et al, Biochem.Biophys. Res. Commun. 2008, 374(1):84-89); ovarian cancer (Bazzaro etal, Clin. Cancer Res. 2008, 14(22):7340-7347); breast cancer (Lee et al,Cancer Res. 2008, 68(18):7561-7569; Park et al, Oncol. Rep. 2011, 25:1677-81; Rey et al, Eur. J. Cell Biol. 2011, 90: 128-35); prostatecancer (Seidel et al, Biochem Pharmacol. 2015 (15)00714-5); pancreaticcancer (Nawrocki et al, Cancer Res. 2006, 66(7):3773-3781); renal cancer(Cha et al, Clin. Cancer Res. 2009, 15(3): 840-850); hepatocellularcancer (Ding et al, FEBS Lett. 2013, 587:880-6; Kanno et al, Oncol. Rep.2012, 28: 867-73); lymphomas (Ding et al, Cancer Cell Int. 2014, 14:139;Amengual et al, Clin Cancer Res. 2015, 21(20):4663-75); and leukemiassuch as acute myeloid leukemia (AML) (Fiskus et al, Blood 2008,112(7):2896-2905) and acute lymphoblastic leukemia (ALL)(Rodriguez-Gonzalez et al, Blood 2008, 112(11): Abstract 1923)).

Inhibition of HDAC6 may also have a role in cardiovascular disease,including pressure overload, chronic ischemia, andinfarction-reperfusion injury (Tannous et al, Circulation 2008, 117(24):3070-3078); bacterial infection, including those caused byuropathogenic Escherichia coli (Dhakal and Mulve, J. Biol. Chem. 2008,284(1):446-454); neurological diseases caused by accumulation ofintracellular protein aggregates such as Alzheimer's, Parkinson's andHuntington's disease (reviewed in Simoes-Pires et al, Mol Neurodegener.2013, 8: 7) or central nervous system trauma caused by tissue injury,oxidative-stress induced neuronal or axomal degeneration (Rivieccio etal, Proc. Natl. Acad. Sci. USA 2009, 106(46):19599-195604); andinflammation and autoimmune diseases through enhanced T cell-mediatedimmune tolerance at least in part through effects on regulatory T cells,including rheumatoid arthritis, psoriasis, spondylitis arthritis,psoriatic arthritis, multiple sclerosis, lupus, colitis and graft versushost disease (reviewed in Wang et al, Nat. Rev. Drug Disc. 20098(12):969-981; Vishwakarma et al, Int Immunopharmacol. 2013, 16:72-8;Kalin et al, J. Med Chem. 2012, 55:639-51); and fibrotic disease,including kidney fibrosis (Choi et al, Vascul Pharmacol. 201572:130-140).

Four HDAC inhibitors are currently approved for the treatment of somecancers. These are suberanilohydroxamic acid (Vorinostat; Zolinza®) forthe treatment of cutaneous T cell lymphoma and multiple myeloma;Romidepsin (FK228; FR901228; Istodax®) for the treatment of peripheral Tcell lymphoma; Panobinostat (LBH-589; Farydak®) for the treatment ofmultiple myeloma; and belinostat (PXD101; Beleodaq®) for the treatmentof peripheral T cell lymphoma. However, these drugs are of limitedeffectiveness and can give rise to unwanted side effects. Thus there isa need for drugs with an improved safety-efficacy profile.

Given the complex function of HDAC6 and their potential utility in thetreatment of proliferative diseases, neurological diseases, andinflammatory diseases, there is a need for HDAC inhibitors (e.g., HDAC6inhibitors) with good therapeutic properties.

SUMMARY OF THE INVENTION

One aspect of the invention relates to compounds of Formula I:

and pharmaceutically acceptable salts, prodrugs, solvates, hydrates,tautomers and isomers thereof, wherein:

X¹ and X² are each independently CR¹R², NR³, O, C═O, SO₂, S(O) or S;

X³, X⁴ and X⁵ are each independently CR¹R², C═O, S(O) or SO₂;

Y¹ and Y⁴ are each independently N or CR¹;

Y² and Y³ are each independently N or CR¹ when not bonded to —C(O)NHOHand Y² and Y³ are C when bonded to —C(O)NHOH;

L is a bond, —(CR¹R²)_(n)—, —C(O)—, —C(O)O—, —C(O)NR³—, —S(O)₂—,—S(O)₂NR³—, —S(O)—, —S(O)NR³—, —C(O)(CR¹R²)_(n)O—, or —C(O)(CR¹R²)_(n);

R is independently, and at each occurrence, —H, —C₁-C₆alkyl,—C₂-C₆alkenyl, —C₄-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl,—C₅-C₁₂spirocycle, heterocyclyl, spiroheterocyclyl, aryl, or heteroarylcontaining 1-5 heteroatoms selected from the group consisting of N, S,P, or O, wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl,spirocycle, heterocyclyl, spiroheterocyclyl, aryl, or heteroaryl isoptionally substituted with one or more —OH, halogen, oxo, —NO₂, —CN,—R¹, —R², —OR³, —NHR³, —NR³R⁴, —S(O)₂NR³R⁴, —S(O)₂R¹, —C(O)R¹, —CO₂R¹,—NR³S(O)₂R¹, —S(O)R¹, —S(O)NR³R⁴, —NR³S(O)R¹, heterocycle, aryl, orheteroaryl, with the proviso that when L is —C(O)— the spiroheterocyclylis not bound to L via a nitrogen atom;

R¹ and R² are independently, and at each occurrence, —H, R³, R⁴,—C₁-C₆alkyl, —C₂-C₆alkenyl, —C₄-C₈cycloalkenyl, —C₂-C₆alkynyl,—C₃-C₈cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1-5heteroatoms selected from the group consisting of N, S, P, or O, —OH,halogen, —NO₂, —CN, —NHC₁-C₆alkyl, —N(C₁-C₆alkyl)₂,—S(O)₂N(C₁-C₆alkyl)₂, —N(C₁-C₆alkyl)S(O)₂R⁵, —S(O)₂(C₁-C₆alkyl),—(C₁-C₆alkyl)S(O)₂R⁵, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)S(O)₂C₁-C₆alkyl, or (CHR⁵)_(n)NR³R⁴, wherein each alkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, orheteroaryl is optionally substituted with one or more substituentsselected from —OH, halogen, —NO₂, oxo, —CN, —R⁵, —OR³, —NHR³, NR³R⁴,—S(O)₂N(R³)₂—, —S(O)₂R⁵, —C(O)R⁵, —CO₂R⁵, —NR³S(O)₂R⁵, —S(O)R⁵,—S(O)NR³R⁴, —NR³S(O)R⁵, heterocycle, aryl, or heteroaryl containing 1-5heteroatoms selected from the group consisting of N, S, P, or O;

or R¹ and R² may combine with the carbon atom to which they are bothattached to form a spirocycle, spiroheterocycle, or a spirocycloalkenyl;

or R¹ and R², when on adjacent atoms, can combine to form a heterocycle,cycloalkyl, aryl, heteroaryl containing 1-5 heteroatoms selected fromthe group consisting of N, S, P, or O, or cycloalkenyl;

or R¹ and R², when on non-adjacent atoms, can combine to form a bridgingcycloalkyl or heterocycloalkyl wherein the bridge between X¹ and X⁴cannot contain exactly one carbon;

R³ and R⁴ are independently, and at each occurrence, —H, —C₁-C₆alkyl,—C₂-C₆alkenyl, —C₄-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl,heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected fromthe group consisting of N, S, P, or O, —S(O)₂N(C₁-C₆alkyl)₂,—S(O)₂(C₁-C₆alkyl), —(C₁-C₆alkyl)S(O)₂R⁵, —C(O)C₁-C₆alkyl,—CO₂C₁-C₆alkyl, or —(CHR⁵)_(n)N(C₁₋C₆alkyl)₂, wherein each alkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, andheteroaryl is optionally substituted with one or more substituentsselected from —OH, halogen, —NO₂, oxo, —CN, —R⁵, —O(C₁-C₆)alkyl,—NH(C₁-C₆)alkyl, N(C₁-C₆alkyl)₂, —S(O)₂N(C₁-C₆alkyl)₂,—S(O)₂NHC₁-C₆alkyl, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)S(O)₂C₁-C₆alkyl, —S(O)R⁵, —S(O)N(C₁-C₆alkyl)₂,—N(C₁-C₆alkyl)S(O)R⁵, heterocycle, aryl, or heteroaryl containing 1-5heteroatoms selected from the group consisting of N, S, P, or O;

R⁵ is independently, and at each occurrence, —H, —C₁-C₆alkyl,—C₂-C₆alkenyl, —C₃-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl,heterocyclyl, aryl, heteroaryl, —OH, halogen, —NO₂, —CN, —NHC₁-C₆alkyl,—N(C₁-C₆alkyl)₂, —S(O)₂NH(C₁-C₆alkyl), —S(O)₂N(C₁-C₆alkyl)₂,—S(O)₂C₁-C₆alkyl, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)SO₂C₁-C₆alkyl, —S(O)(C₁-C₆alkyl), —S(O)N(C₁-C₆alkyl)₂,—N(C₁-C₆alkyl)S(O)(C₁-C₆alkyl) or (CH₂)_(n)N(C₁-C₆alkyl)₂; and

n is independently, and at each occurrence, an integer from 0 to 6;

provided that X¹, X², X³, X⁴ and X⁵ are not all CR¹R² at the same time.

Another aspect of the invention relates to compounds of Formula II:

and pharmaceutically acceptable salts, prodrugs, solvates, hydrates,tautomers and isomers thereof, wherein:

X¹ is independently CR¹R², NR³, O, C═O, SO₂, S(O) or S;

X², X³, X⁴ and X⁵ are each independently CR¹R², C═O, S(O) or SO₂;

Y¹ and Y⁴ are each independently N or CR¹;

Y² and Y³ are each independently N or CR¹ when not bonded to —C(O)NHOHand Y² and Y³ are C when bonded to —C(O)NHOH;

L is a bond, —(CR¹R²)_(n)—, —C(O)—, —C(O)O—, —C(O)NR³—, —S(O)₂—,—S(O)₂NR³—, —S(O)—, —S(O)NR³—, —C(O)(CR¹R²)_(n)O—, or —C(O)(CR¹R²)_(n);

R is independently, and at each occurrence, —H, —C₁-C₆alkyl,—C₂-C₆alkenyl, —C₄-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl,—C₅-C₁₂spirocycle, heterocyclyl, spiroheterocyclyl, aryl, or heteroarylcontaining 1-5 heteroatoms selected from the group consisting of N, S,P, or O, wherein each alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl,spirocycle, heterocyclyl, spiroheterocyclyl, aryl, or heteroaryl isoptionally substituted with one or more —OH, halogen, oxo, —NO₂, —CN,—R¹, —R², —OR³, —NHR³, —NR³R⁴, —S(O)₂NR³R⁴, —S(O)₂R¹, —C(O)R¹, or—CO₂R¹, —NR³S(O)₂R¹, —S(O)R¹, —S(O)NR³R⁴, —NR³S(O)R¹, heterocycle, aryl,or heteroaryl, with the proviso that when L is —C(O)— thespiroheterocyclyl is not bound to L via a nitrogen atom;

R¹ and R² are independently, and at each occurrence, —H, R³, R⁴,—C₁-C₆alkyl, —C₂-C₆alkenyl, —C₄-C₈cycloalkenyl, —C₂-C₆alkynyl,—C₃-C₈cycloalkyl, heterocyclyl, aryl, heteroaryl containing 1-5heteroatoms selected from the group consisting of N, S, P, or O, —OH,halogen, —NO₂, —CN, —NHC₁-C₆alkyl, —N(C₁-C₆alkyl)₂,—S(O)₂N(C₁-C₆alkyl)₂, —N(C₁-C₆alkyl)S(O)₂R⁵, —S(O)₂(C₁-C₆alkyl),—(C₁-C₆alkyl)S(O)₂R⁵, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)S(O)₂C₁-C₆alkyl, or (CHR⁵)_(n)NR³R⁴, wherein each alkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, orheteroaryl is optionally substituted with one or more substituentsselected from —OH, halogen, —NO₂, oxo, —CN, —R⁵, —OR³, —NHR³, NR³R⁴,—S(O)₂N(R³)₂—, —S(O)₂R⁵, —C(O)R⁵, —CO₂R⁵, —NR³S(O)₂R⁵, —S(O)R⁵,—S(O)NR³R⁴, —NR³S(O)R⁵, heterocycle, aryl, or heteroaryl;

or R¹ and R² may combine with the carbon atom to which they are bothattached to form a spirocycle, spiroheterocycle, or a spirocycloalkenyl;

or R¹ and R², when on adjacent atoms, can combine to form a heterocycle,cycloalkyl, aryl, heteroaryl containing 1-5 heteroatoms selected fromthe group consisting of N, S, P, or O, or cycloalkenyl;

or R¹ and R², when on non-adjacent atoms, can combine to form a bridgingcycloalkyl or heterocycloalkyl;

R³ and R⁴ are independently, and at each occurrence, —H, —C₁-C₆alkyl,—C₂-C₆alkenyl, —C₄-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl,heterocyclyl, aryl, heteroaryl containing 1-5 heteroatoms selected fromthe group consisting of N, S, P, or O, —S(O)₂N(C₁-C₆alkyl)₂,—S(O)₂(C₁-C₆alkyl), —(C₁-C₆alkyl)S(O)₂R⁵, —C(O)C₁-C₆alkyl,—CO₂C₁-C₆alkyl, or —(CHR⁵)_(n)N(C₁-C₆alkyl)₂, wherein each alkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, andheteroaryl is optionally substituted with one or more substituentsselected from —OH, halogen, —NO₂, oxo, —CN, —R⁵, —O(C₁-C₆)alkyl,—NH(C₁-C₆)alkyl, N(C₁-C₆alkyl)₂, —S(O)₂N(C₁-C₆alkyl)₂,—S(O)₂NHC₁-C₆alkyl, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)S(O)₂C₁-C₆alkyl, —S(O)R⁵, —S(O)N(C₁-C₆alkyl)₂,—N(C₁-C₆alkyl)S(O)R⁵, heterocycle, aryl, or heteroaryl containing 1-5heteroatoms selected from the group consisting of N, S, P, or O;

R⁵ is independently, and at each occurrence, —H, —C₁-C₆alkyl,—C₂-C₆alkenyl, —C₃-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl,heterocyclyl, aryl, heteroaryl, —OH, halogen, —NO₂, —CN, —NHC₁-C₆alkyl,—N(C₁-C₆alkyl)₂, —S(O)₂NH(C₁-C₆alkyl), —S(O)₂N(C₁-C₆alkyl)₂,—S(O)₂C₁-C₆alkyl, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)SO₂C₁-C₆alkyl, —S(O)(C₁-C₆alkyl), —S(O)N(C₁-C₆alkyl)₂,—N(C₁-C₆alkyl)S(O)(C₁-C₆alkyl) or (CH₂)_(n)N(C₁-C₆alkyl)₂; and

n is independently and at each occurrence an integer from 0 to 6;

provided that X¹, X², X³, X⁴ and X⁵ are not all CR¹R² at the same time.

Another aspect of the invention relates to a method of treating adisease or disorder associated with HDAC6 modulation in a subject inneed thereof, comprising administering to the subject an effectiveamount of a compound of Formulae I or II.

Another aspect of the invention is directed to a method of inhibitingHDAC6. The method involves administering to a patient in need thereof aneffective amount of a compound of Formulae I or II.

Another aspect of the invention is directed to pharmaceuticalcompositions comprising a compound of Formulae I or II and apharmaceutically acceptable carrier. The pharmaceutically acceptablecarrier can further include an excipient, diluent, or surfactant. Thepharmaceutical composition can be effective for treating a disease ordisorder associated with HDAC6 modulation in a subject in need thereof.The pharmaceutical compositions can comprise the compounds of thepresent invention for use in treating diseases described herein. Thecompositions can contain at least one compound of the invention and apharmaceutically acceptable carrier. The invention also provides the useof the compounds described herein in the manufacture of a medicament forthe treatment of a disease associated with HDACs.

The present invention also provides methods for the treatment of humandiseases or disorders including, without limitation, oncological,neurological, inflammatory, autoimmune, infectious, metabolic,hematologic, or cardiovascular diseases or disorders.

The present invention also provides compounds that are useful ininhibiting of zinc-dependent HDAC enzymes, and in particular HDAC6.These compounds can also be useful in the treatment of diseasesincluding cancer.

The present invention further provides compounds that can inhibit HDAC6.In some embodiments, the efficacy-safety profile of the compounds of thecurrent invention can be improved relative to other known HDAC (e.g.HDAC6) inhibitors. Additionally, the present technology also has theadvantage of being able to be used for a number of different types ofdiseases, including cancer and non-cancer indications. Additionalfeatures and advantages of the present technology will be apparent toone of skill in the art upon reading the Detailed Description of theInvention, below.

DETAILED DESCRIPTION OF THE INVENTION

HDAC6 is a zinc-dependent histone deacetylase that has two catalyticdomains. HDAC6 can interact with and deacetylate non-histone proteins,including HSP90 and α-tubulin. Acetylation of HSP90 is associated withloss of function of HSP90. HDAC6 is also implicated in the degradationof misfolded proteins as part of the aggresome. Accordingly, inhibitionof HDAC6 can have downstream effects that can play a role in thedevelopment of certain diseases such as cancer. The present inventionprovides inhibitors of HDAC6 and methods for using the same to treatdisease.

In a first aspect of the invention, compounds of the Formulae I or IIare described:

and pharmaceutically acceptable salts, prodrugs, solvates, hydrates,tautomers, and isomers thereof, wherein R, L, X¹, X², X³, X⁴, X⁵, Y¹,Y², Y³, and Y⁴ are described as above.

In a second aspect of the invention, compounds of the Formula II aredescribed:

and pharmaceutically acceptable salts, prodrugs, solvates, hydrates,tautomers, and isomers thereof, wherein R, L, X¹, X², X³, X⁴, X⁵, Y¹,Y², Y³, and Y⁴ are described as above.

The details of the invention are set forth in the accompanyingdescription below. Although methods and materials similar or equivalentto those described herein can be used in the practice or testing of thepresent invention, illustrative methods and materials are now described.Other features, objects, and advantages of the invention will beapparent from the description and from the claims. In the specificationand the appended claims, the singular forms also include the pluralunless the context clearly dictates otherwise. Unless defined otherwise,all technical and scientific terms used herein have the same meaning ascommonly understood by one of ordinary skill in the art to which thisinvention belongs. All patents and publications cited in thisspecification are incorporated herein by reference in their entireties.

Definitions

The articles “a” and “an” are used in this disclosure to refer to one ormore than one (i.e., to at least one) of the grammatical object of thearticle. By way of example, “an element” means one element or more thanone element.

The term “and/or” is used in this disclosure to mean either “and” or“or” unless indicated otherwise.

The term “optionally substituted” is understood to mean that a givenchemical moiety (e.g. an alkyl group) can (but is not required to) bebonded other substituents (e.g. heteroatoms). For instance, an alkylgroup that is optionally substituted can be a fully saturated alkylchain (i.e. a pure hydrocarbon). Alternatively, the same optionallysubstituted alkyl group can have substituents different from hydrogen.For instance, it can, at any point along the chain be bounded to ahalogen atom, a hydroxyl group, or any other substituent describedherein. Thus the term “optionally substituted” means that a givenchemical moiety has the potential to contain other functional groups,but does not necessarily have any further functional groups.

The term “aryl” refers to cyclic, aromatic hydrocarbon groups that have1 to 2 aromatic rings, including monocyclic or bicyclic groups such asphenyl, biphenyl or naphthyl. Where containing two aromatic rings(bicyclic, etc.), the aromatic rings of the aryl group may be joined ata single point (e.g., biphenyl), or fused (e.g., naphthyl). The arylgroup may be optionally substituted by one or more substituents, e.g., 1to 5 substituents, at any point of attachment. Exemplary substituentsinclude, but are not limited to, —H, -halogen, —O—C₁-C₆alkyl,—C₁-C₆alkyl, —OC₂-C₆alkenyl, —OC₂-C₆alkynyl, —C₂-C₆alkenyl,—C₂-C₆alkynyl, —OH, —OP(O)(OH)₂, —OC(O)C₁-C₆alkyl, —C(O)C₁-C₆alkyl,—OC(O)OC₁-C₆alkyl, —NH₂, —NH(C₁-C₆alkyl), —N(C₁-C₆alkyl)₂,—S(O)₂—C₁-C₆alkyl, —S(O)NHC₁-C₆alkyl, and —S(O)N(C₁-C₆alkyl)₂. Thesubstituents can themselves be optionally substituted. Furthermore whencontaining two fused rings the aryl groups herein defined may have anunsaturated or partially saturated ring fused with a fully saturatedring. Exemplary ring systems of these aryl groups include indanyl,indenyl, tetrahydronaphthalenyl, and tetrahydrobenzoannulenyl.

Unless otherwise specifically defined, “heteroaryl” means a monovalentmonocyclic aromatic radical of 5 to 24 ring atoms or a polycyclicaromatic radical, containing one or more ring heteroatoms selected fromN, S, P, or O, the remaining ring atoms being C. Heteroaryl as hereindefined also means a bicyclic heteroaromatic group wherein theheteroatom is selected from N, S, P, or O. The aromatic radical isoptionally substituted independently with one or more substituentsdescribed herein. Examples include, but are not limited to, furyl,thienyl, pyrrolyl, pyridyl, pyrazolyl, pyrimidinyl, imidazolyl,isoxazolyl, oxazolyl, oxadiazolyl, pyrazinyl, indolyl, thiophen-2-yl,quinolyl, benzopyranyl, isothiazolyl, thiazolyl, thiadiazole, indazole,benzimidazolyl, thieno[3,2-b]thiophene, triazolyl, triazinyl,imidazo[1,2-b]pyrazolyl, furo[2,3-c]pyridinyl, imidazo[1,2-a]pyridinyl,indazolyl, pyrrolo[2,3-c]pyridinyl, pyrrolo[3,2-c]pyridinyl,pyrazolo[3,4-c]pyridinyl, thieno[3,2-c]pyridinyl,thieno[2,3-c]pyridinyl, thieno[2,3-b]pyridinyl, benzothiazolyl, indolyl,indolinyl, indolinonyl, dihydrobenzothiophenyl, dihydrobenzofuranyl,benzofuran, chromanyl, thiochromanyl, tetrahydroquinolinyl,dihydrobenzothiazine, dihydrobenzoxanyl, quinolinyl, isoquinolinyl,1,6-naphthyridinyl, benzo[de]isoquinolinyl,pyrido[4,3-b][1,6]naphthyridinyl, thieno[2,3-b]pyrazinyl, quinazolinyl,tetrazolo[1,5-a]pyridinyl, [1,2,4]triazolo[4,3-a]pyridinyl, isoindolyl,pyrrolo[2,3-b]pyridinyl, pyrrolo[3,4-b]pyridinyl,pyrrolo[3,2-b]pyridinyl, imidazo[5,4-b]pyridinyl,pyrrolo[1,2-a]pyrimidinyl, tetrahydro pyrrolo[1,2-a]pyrimidinyl,3,4-dihydro-2H-1 X²-pyrrolo[2,1-b]pyrimidine, dibenzo[b,d]thiophene,pyridin-2-one, furo[3,2-c]pyridinyl, furo[2,3-c]pyridinyl,1H-pyrido[3,4-b][1,4]thiazinyl, benzooxazolyl, benzoisoxazolyl,furo[2,3-b]pyridinyl, benzothiophenyl, 1,5-naphthyridinyl,furo[3,2-b]pyridine, [1,2,4]triazolo[1,5-a]pyridinyl, benzo[1,2,3]triazolyl, imidazo[1,2-a]pyrimidinyl,[1,2,4]triazolo[4,3-b]pyridazinyl, benzo[c][1,2,5]thiadiazolyl,benzo[c][1,2,5]oxadiazole, 1,3-dihydro-2H-benzo[d]imidazol-2-one,3,4-dihydro-2H-pyrazolo [1,5-b][1,2]oxazinyl,4,5,6,7-tetrahydropyrazolo[1,5-a]pyridinyl, thiazolo[5,4-d]thiazolyl,imidazo[2,1-b][1,3,4]thiadiazolyl, thieno[2,3-b]pyrrolyl, 3H-indolyl,and derivatives thereof. Furthermore when containing two fused rings theheteroaryl groups herein defined may have an unsaturated or partiallysaturated ring fused with a fully saturated ring. Exemplary ring systemsof these heteroaryl groups include indolinyl, indolinonyl,dihydrobenzothiophenyl, dihydrobenzofuran, chromanyl, thiochromanyl,tetrahydroquinolinyl, dihydrobenzothiazine,3,4-dihydro-1H-isoquinolinyl, 2,3-dihydrobenzofuran, indolinyl, indolyl,and dihydrobenzoxanyl.

“Alkyl” refers to a straight or branched chain saturated hydrocarbon.C₁-C₆alkyl groups contain 1 to 6 carbon atoms. Examples of a C₁-C₆alkylgroup include, but are not limited to, methyl, ethyl, propyl, butyl,pentyl, isopropyl, isobutyl, sec-butyl and tert-butyl, isopentyl andneopentyl.

The term “alkenyl” means an aliphatic hydrocarbon group containing acarbon-carbon double bond and which may be straight or branched havingabout 2 to about 6 carbon atoms in the chain. Preferred alkenyl groupshave 2 to about 4 carbon atoms in the chain. Branched means that one ormore lower alkyl groups such as methyl, ethyl, or propyl are attached toa linear alkenyl chain. Exemplary alkenyl groups include ethenyl,propenyl, n-butenyl, and i-butenyl. A C₂-C₆ alkenyl group is an alkenylgroup containing between 2 and 6 carbon atoms.

The term “alkynyl” means an aliphatic hydrocarbon group containing acarbon-carbon triple bond and which may be straight or branched havingabout 2 to about 6 carbon atoms in the chain. Preferred alkynyl groupshave 2 to about 4 carbon atoms in the chain. Branched means that one ormore lower alkyl groups such as methyl, ethyl, or propyl are attached toa linear alkynyl chain. Exemplary alkynyl groups include ethynyl,propynyl, n-butynyl, 2-butynyl, 3-methylbutynyl, and n-pentynyl. A C₂-C₆alkynyl group is an alkynyl group containing between 2 and 6 carbonatoms.

The term “cycloalkyl” means monocyclic or polycyclic saturated carbonrings containing 3-18 carbon atoms. Examples of cycloalkyl groupsinclude, without limitations, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, cycloheptanyl, cyclooctanyl, norboranyl, norborenyl,bicyclo[2.2.2]octanyl, or bicyclo[2.2.2]octenyl. A C₃-C₈ cycloalkyl is acycloalkyl group containing between 3 and 8 carbon atoms. A cycloalkylgroup can be fused (e.g., decalin) or bridged (e.g., norbornane).

The term “cycloalkenyl” means monocyclic, non-aromatic unsaturatedcarbon rings containing 3-18 carbon atoms. Examples of cycloalkenylgroups include, without limitation, cyclopentenyl, cyclohexenyl,cycloheptenyl, cyclooctenyl, and norborenyl. A C₃-C₈ cycloalkenyl is acycloalkenyl group containing between 3 and 8 carbon atoms.

The terms “heterocyclyl” or “heterocycloalkyl” or “heterocycle” refer tomonocyclic or polycyclic 3 to 24-membered rings containing carbon andheteroatoms taken from oxygen, nitrogen, or sulfur and wherein there isnot delocalized π electrons (aromaticity) shared among the ring carbonor heteroatoms. Heterocyclyl rings include, but are not limited to,oxetanyl, azetadinyl, tetrahydrofuranyl, pyrrolidinyl, oxazolinyl,oxazolidinyl, thiazolinyl, thiazolidinyl, pyranyl, thiopyranyl,tetrahydropyranyl, dioxalinyl, piperidinyl, morpholinyl,thiomorpholinyl, thiomorpholinyl S-oxide, thiomorpholinyl S-dioxide,piperazinyl, azepinyl, oxepinyl, diazepinyl, tropanyl, and homotropanyl.A heteroycyclyl or heterocycloalkyl ring can also be fused or bridged,e.g., can be a bicyclic ring.

As used herein, the term “halo” or “halogen” means fluoro, chloro,bromo, or iodo.

The term “carbonyl” refers to a functional group composing a carbon atomdouble-bonded to an oxygen atom. It can be abbreviated herein as “oxo”,as C(O), or as C═O.

“Spirocycle” or “spirocyclic” means carbogenic bicyclic ring systemswith both rings connected through a single atom. The ring can bedifferent in size and nature, or identical in size and nature. Examplesinclude spiropentane, spriohexane, spiroheptane, spirooctane,spirononane, or spirodecane. One or both of the rings in a spirocyclecan be fused to another ring carbocyclic, heterocyclic, aromatic, orheteroaromatic ring. One or more of the carbon atoms in the spirocyclecan be substituted with a heteroatom (e.g., O, N, S, or P). A C₃-C₁₂spirocycle is a spirocycle containing between 3 and 12 carbon atoms. Oneor more of the carbon atoms can be substituted with a heteroatom.

The term “spirocyclic heterocycle” or “spiroheterocycle” is understoodto mean a spirocycle wherein at least one of the rings is a heterocycle(e.g., at least one of the rings is furanyl, morpholinyl, orpiperadinyl).

The disclosure also includes pharmaceutical compositions comprising aneffective amount of a disclosed compound and a pharmaceuticallyacceptable carrier. Representative “pharmaceutically acceptable salts”include, e.g., water-soluble and water-insoluble salts, such as theacetate, amsonate (4,4-diaminostilbene-2,2-disulfonate),benzenesulfonate, benzonate, bicarbonate, bisulfate, bitartrate, borate,bromide, butyrate, calcium, calcium edetate, camsylate, carbonate,chloride, citrate, clavulariate, dihydrochloride, edetate, edisylate,estolate, esylate, fiunarate, gluceptate, gluconate, glutamate,glycollylarsanilate, hexafluorophosphate, hexylresorcinate, hydrabamine,hydrobromide, hydrochloride, hydroxynaphthoate, iodide, sethionate,lactate, lactobionate, laurate, magnesium, malate, maleate, mandelate,mesylate, methylbromide, methylnitrate, methylsulfate, mucate,napsylate, nitrate, N-methylglucamine ammonium salt,3-hydroxy-2-naphthoate, oleate, oxalate, palmitate, pamoate(1,1-methene-bis-2-hydroxy-3-naphthoate, einbonate), pantothenate,phosphate/diphosphate, picrate, polygalacturonate, propionate,p-toluenesulfonate, salicylate, stearate, subacetate, succinate,sulfate, sulfosalicylate, suramate, tannate, tartrate, teoclate,tosylate, triethiodide, and valerate salts.

The term “stereoisomers” refers to the set of compounds which have thesame number and type of atoms and share the same bond connectivitybetween those atoms, but differ in three dimensional structure. The term“stereoisomer” refers to any member of this set of compounds.

The term “diastereomers” refers to the set of stereoisomers which cannotbe made superimposable by rotation around single bonds. For example,cis- and trans-double bonds, endo- and exo-substitution on bicyclic ringsystems, and compounds containing multiple stereogenic centers withdifferent relative configurations are considered to be diastereomers.The term “diastereomer” refers to any member of this set of compounds.In some examples presented, the synthetic route may produce a singlediastereomer or a mixture of diastereomers. In some cases thesediastereomers were separated and in other cases a wavy bond is used toindicate the structural element where configuration is variable.

The term “enantiomers” refers to a pair of stereoisomers which arenon-superimposable mirror images of one another. The term “enantiomer”refers to a single member of this pair of stereoisomers. The term“racemic” refers to a 1:1 mixture of a pair of enantiomers.

The term “tautomers” refers to a set of compounds that have the samenumber and type of atoms, but differ in bond connectivity and are inequilibrium with one another. A “tautomer” is a single member of thisset of compounds. Typically a single tautomer is drawn but it isunderstood that this single structure is meant to represent all possibletautomers that might exist. Examples include enol-ketone tautomerism.When a ketone is drawn it is understood that both the enol and ketoneforms are part of the invention.

An “effective amount” when used in connection with a compound is anamount effective for treating or preventing a disease in a subject asdescribed herein.

The term “carrier”, as used in this disclosure, encompasses carriers,excipients, and diluents and means a material, composition or vehicle,such as a liquid or solid filler, diluent, excipient, solvent orencapsulating material, involved in carrying or transporting apharmaceutical agent from one organ, or portion of the body, to anotherorgan, or portion of the body of a subject.

The term “treating” with regard to a subject, refers to improving atleast one symptom of the subject's disorder. Treating includes curing,improving, or at least partially ameliorating the disorder.

The term “disorder” is used in this disclosure to mean, and is usedinterchangeably with, the terms disease, condition, or illness, unlessotherwise indicated.

The term “administer”, “administering”, or “administration” as used inthis disclosure refers to either directly administering a disclosedcompound or pharmaceutically acceptable salt of the disclosed compoundor a composition to a subject, or administering a prodrug derivative oranalog of the compound or pharmaceutically acceptable salt of thecompound or composition to the subject, which can form an equivalentamount of active compound within the subject's body.

The term “prodrug,” as used in this disclosure, means a compound whichis convertible in vivo by metabolic means (e.g., by hydrolysis) to adisclosed compound. Furthermore, as used herein a prodrug is a drugwhich is inactive in the body, but is transformed in the body typicallyeither during absorption or after absorption from the gastrointestinaltract into the active compound. The conversion of the prodrug into theactive compound in the body may be done chemically or biologically(i.e., using an enzyme).

The term “solvate” refers to a complex of variable stoichiometry formedby a solute and solvent. Such solvents for the purpose of the inventionmay not interfere with the biological activity of the solute. Examplesof suitable solvents include, but are not limited to, water, MeOH, EtOH,and AcOH. Solvates wherein water is the solvent molecule are typicallyreferred to as hydrates. Hydrates include compositions containingstoichiometric amounts of water, as well as compositions containingvariable amounts of water.

The term “isomer” refers to compounds that have the same composition andmolecular weight but differ in physical and/or chemical properties. Thestructural difference may be in constitution (geometric isomers) or inthe ability to rotate the plane of polarized light (stereoisomers). Withregard to stereoisomers, the compounds of Formulae I or II may have oneor more asymmetric carbon atom and may occur as racemates, racemicmixtures and as individual enantiomers or diastereomers.

A “patient” or “subject” is a mammal, e.g., a human, mouse, rat, guineapig, dog, cat, horse, cow, pig, or non-human primate, such as a monkey,chimpanzee, baboon or rhesus.

In one embodiment of the compounds of Formula I, X⁵ is CR¹R².

In another embodiment of the compounds of Formula I, X¹ is NR³, O, C═O,SO₂, or S.

In another embodiment of the compounds of Formula I, X¹ is O and X⁵ isCR¹R².

In another embodiment of the compounds of Formula I, L is CH₂.

In another embodiment of the compounds of Formula I, L is —C(O)—.

In another embodiment of the compounds of Formula I, any two or more ofR¹ and R² may combine with the carbon atom or atoms to which they areattached to form a heterocycle, a cycloalkyl, or a spirocycle only whenX¹ is O, S, or N.

In another embodiment of the compounds of Formula I, any two or more ofR¹ and R², when on adjacent atoms, may attach to form a heterocycle,cycloalkyl, aryl, heteroaryl containing 1-5 heteroatoms, or cycloalkenylonly when X¹ is O, S, or N.

In another embodiment of the compounds of Formula I, any two or more ofR¹, and R², when on non-adjacent atoms, can combine to form a bridgingcycloalkyl or heterocycloalkyl only when X¹ is O, S, or N.

In one embodiment of the compounds of Formula II, X⁵ is CR¹R².

In another embodiment of the compounds of Formula II, X¹ is NR³, O, C═O,SO₂, or S.

In another embodiment of the compounds of Formula II, X¹ is O and X⁵ isCR¹R².

In another embodiment of the compounds of Formula II, L is CH₂.

In another embodiment of the compounds of Formula II, L is —C(O)—.

In another embodiment of the compounds of Formula II, any two or more ofR¹, and R² may combine with the carbon atom or atoms to which they areattached to form a heterocycle, a cycloalkyl, or a spirocycle only whenX¹ is O, S, or N; or two or more of R¹ and R² when on adjacent atoms,may attach to form a heterocycle, cycloalkyl, aryl, heteroarylcontaining 1-5 heteroatoms, or cycloalkenyl only when X¹ is O, S, or N;or two or more of R¹ and R², when on non-adjacent atoms, can combine toform a bridging cycloalkyl or heterocycloalkyl only when X¹ is O, S, orN.

In one embodiment, when X² and X⁵ are both C═O, X¹ is not NR⁵.

In one embodiment of the compounds of Formula I are described compoundsof the Formula IA:

and pharmaceutically acceptable salts, prodrugs, solvates, hydrates,tautomers or isomer thereof; where R, L, X¹, X², X³, X⁴, X⁵, Y¹, Y³, andY⁴ are defined as above in Formula I.

In some embodiments of the invention, the compounds of Formula IA may beof the formula IA-1:

In other embodiments of the compounds of Formula IA, the compound is ofthe formula IA-2:

In yet other another embodiments of the compounds of Formula IA, thecompound is of the formula IA-3:

In one embodiment of the compounds of Formula I are also disclosedcompounds of the Formula IB:

and pharmaceutically acceptable salts, prodrugs, solvates, hydrates,enantiomers and isomers thereof where R, L, X¹, X², X³, X⁴, X⁵, Y¹, Y²,and Y⁴ are defined as above in Formula I.

In one embodiment of the compounds of Formula II are described compoundsof the Formula IIA:

and pharmaceutically acceptable salts, prodrugs, solvates, hydrates,tautomers or isomer thereof; where R, L, X¹, X², X³, X⁴, X⁵, Y¹, Y³, andY⁴ are defined as above in Formula II.

In other embodiments of the compounds of Formula IIA, the compound is ofthe formula IIA-1:

In yet other embodiments of the compounds of Formula IIA, the compoundis of the formula (IIA-2):

In other embodiments of the compounds of Formula II, the compound mayalso be of the formula II-B:

In some embodiments of Formula (I), X¹ is O. In another embodiment, X¹is O and X² is CR¹R². In yet another embodiment, X¹ is O, X² is CR¹R²,and X³ is CR¹R². In another embodiment, X¹ is O, X² is CR¹R², X³ isCR¹R², and X⁴ is CR¹R². In yet another embodiment, X¹ is O, X² is CR¹R²,X³ is CR¹R², X⁴ is CR¹R², and X⁵ is CR¹R². In yet another embodiment, X¹is O, X² is CR¹R², X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², and Y¹ is CR¹.In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴ is CR¹R²,X⁵ is CR¹R², Y¹ is CR¹, and Y³ is CR¹. In yet another embodiment, X¹ isO, X² is CR¹R², X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ isCR¹, and Y⁴ is CR¹. In another embodiment, X¹ is O, X² is CR¹R², X³ isCR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, and Y²is C. In yet another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis —C(O)—. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis a bond. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis —S(O)₂—. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis —S(O)₂NR³—. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R²,X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, andL is —C(O)NR³—. In another embodiment, X¹ is O, X² is CR¹R², X³ isCR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² isC, and L is —C(O)O—. In yet another embodiment, X¹ is O, X² is CR¹R², X³is CR¹R², X⁴ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, L is—(CR¹R²)_(n)—.

In some embodiments of Formula (II), X¹ is O. In another embodiment, X¹is O and X² is CR¹R². In yet another embodiment, X¹ is O, X² is CR¹R²,and X³ is CR¹R². In another embodiment, X¹ is O, X² is CR¹R², X³ isCR¹R², and X⁴ is CR¹R². In yet another embodiment, X¹ is O, X² is CR¹R²,X³ is CR¹R², X⁴ is CR¹R², and X⁵ is CR¹R². In yet another embodiment, X¹is O, X² is CR¹R², X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², and Y¹ is CR¹.In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴ is CR¹R²,X⁵ is CR¹R², Y¹ is CR¹, and Y³ is CR¹. In yet another embodiment, X¹ isO, X² is CR¹R², X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ isCR¹, and Y⁴ is CR¹. In another embodiment, X¹ is O, X² is CR¹R², X³ isCR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, and Y²is C. In yet another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis —C(O)—. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis a bond. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis —S(O)₂—. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R², X⁴is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and Lis —S(O)₂NR³—. In another embodiment, X¹ is O, X² is CR¹R², X³ is CR¹R²,X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, andL is —C(O)NR³—. In another embodiment, X¹ is O, X² is CR¹R², X³ isCR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² isC, and L is —C(O)O—. In yet another embodiment, X¹ is O, X² is CR¹R², X³is CR¹R², X⁴ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, L is—(CR¹R²)_(n)—.

In some embodiments of Formula (I), X² is NR³. In another embodiment, X²is NR³ and X¹ is CR¹R². In yet another embodiment, X¹ is CR¹R², X² isNR³, and X³ is CR¹R². In another embodiment, X¹ is CR¹R², X² is NR³, X³is CR¹R², and X⁴ is CR¹R². In yet another embodiment, X¹ is CR¹R², X² isNR³, X³ is CR¹R², X⁴ is CR¹R², and X⁵ is CR¹R². In yet anotherembodiment, X¹ is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵ isCR¹R², and Y¹ is CR¹. In another embodiment, X¹ is CR¹R², X² is NR³, X³is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, and Y³ is CR¹. In yetanother embodiment, X¹ is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵is CR¹R², Y¹ is CR¹, Y³ is CR¹, and Y⁴ is CR¹. In another embodiment, X¹is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹,Y³ is CR¹, Y⁴ is CR¹, and Y² is C. In yet another embodiment, X¹ isCR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹, Y³is CR¹, Y⁴ is CR¹, Y² is C, and L is —C(O)—. In another embodiment, X¹is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ is CR¹,Y³ is CR¹, Y⁴ is CR¹, Y² is C, and L is a bond. In another embodiment,X¹ is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵ is CR¹R², Y¹ isCR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and L is —S(O)₂—. In anotherembodiment, X¹ is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵ isCR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and L is —S(O)₂NR³—. Inanother embodiment, X¹ is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R², X⁵is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and L is —C(O)NR³—.In another embodiment, X¹ is CR¹R², X² is NR³, X³ is CR¹R², X⁴ is CR¹R²,X⁵ is CR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, and L is —C(O)O—.In yet another embodiment, X¹ is CR¹R², X² is NR³, X³ is CR¹R², X⁴ isCR¹R², Y¹ is CR¹, Y³ is CR¹, Y⁴ is CR¹, Y² is C, L is —(CR¹R²)n-

In some embodiments of Formulae (I) and (II), R is H, —C₁-C₆ alkyl,—C₄-C₈ cycloalkenyl, —C₃-C₈ cycloalkyl, —C₅-C₁₂ spirocycle,heterocyclyl, spiroheterocyclyl, aryl, or heteroaryl containing 1 to 5heteroatoms selected from the group consisting of N, S, P, and O,wherein each alkyl, cycloalkenyl, cycloalkyl, spirocycle, heterocyclyl,spiroheterocyclyl, aryl, or heteroaryl is optionally substituted withone or more —OH, halogen, oxo, —NO₂, —CN, —R¹, —R², —OR³, —NHR³, —NR³R⁴,—S(O)₂NR³R⁴, —S(O)₂R¹, —C(O)R¹, or —CO₂R¹, —NR³S(O)₂R¹, —S(O)R¹,—S(O)NR³R⁴, —NR³S(O)R¹, heterocycle, aryl, or heteroaryl containing 1 to5 heteroatoms selected from the group consisting of N, S, P, and O, withthe proviso that R is not bound to L via a nitrogen atom.

In some embodiments of Formulae (I) and (II), n is 1 to 6. In anotherembodiment, n is 0 to 5. In yet another embodiment, n is 0 to 4. In yetanother embodiment, n is 1 to 4. In another embodiment, n is 0 to 3. Inyet another embodiment, n is 0 to 2. In yet another embodiment, n is 0or 1. In another embodiment, n is 1 or 2.

In some embodiments of Formulae (I) and (II), R¹ and R² may combine withthe atom to which they are both attached to form a spirocycle. Inanother embodiment, R¹ and R² combine with the atom to which they areboth attached to form a spiroheterocycle. In another embodiment, R¹ andR² combine with the atom to which they are both attached to form aspirocycloalkenyl.

In some embodiments of Formulae (I) and (II), R¹ and R², when onadjacent atoms, combine to form a heterocycle. In another embodiment, R¹and R², when on adjacent atoms, combine to form a cycloalkyl. In yetanother embodiment, R¹ and R², when on adjacent atoms, combine to form acycloalkenyl. In another embodiment, R¹ and R², when on adjacent atoms,combine to form an aryl. In yet another embodiment, R¹ and R², when onadjacent atoms, combine to form a heteroaryl containing 1 to 5heteroatoms selected from the group consisting of N, S, P, and O.

In some embodiments of Formula (I), R¹ and R², when on non-adjacentatoms, combine to form a bridging cycloalkyl. In another embodiment, R¹and R², when on non-adjacent atoms, combine to form a bridgingcycloalkenyl. In yet another embodiment, R¹ and R², when on non-adjacentatoms, combine to form a heterocycloalkyl.

In an illustrative embodiment, the compound of Formula I is:

-   N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   N-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][15]oxazocine-9-carboxamide;-   N-hydroxy-5-(4-methyltetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   N-hydroxy-5-phenyl-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   5-benzyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   5-benzoyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   5-(cyclohexanecarbonyl)-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   N-hydroxy-5-(phenylsulfonyl)-3,4,5,6-tetrahydro-2H-benzo[b][15]oxazocine-9-carboxamide;-   N9-hydroxy-N5-phenyl-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5,9(6H)-dicarboxamide;    N-hydroxy-5-(N-phenyl    sulfamoyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   5-(cyclohexylmethyl)-N-hydroxy-6-oxo-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   N-hydroxy-5-phenyl-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-9-carboxamide;-   5-benzyl-N-hydroxy-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-9-carboxamide;-   5-benzoyl-N-hydroxy-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-9-carboxamide;-   5-(cyclohexanecarbonyl)-N-hydroxy-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-9-carboxamide;-   N-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-9-carboxamide;-   N-hydroxy-5-(phenylsulfonyl)-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-9-carboxamide;-   N9-hydroxy-N5-phenyl-3,4-dihydro-2H-2,4-methanobenzo[b][1,5]oxazocine-5,9(6H)-dicarboxamide;-   N-hydroxy-5-(N-phenylsulfamoyl)-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][15]oxazocine-9-carboxamide;-   N-hydroxy-5-methyl-2-phenyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   2-benzyl-N-hydroxy-5-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   2-benzoyl-N-hydroxy-5-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   2-(cyclohexanecarbonyl)-N-hydroxy-5-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   N-hydroxy-5-methyl-2-(tetrahydro-2H-pyran-4-carbonyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   N8-hydroxy-5-methyl-N2-phenyl-3,4,5,6-tetrahydrobenzo[f][1,4]diazocine-2,8(1H)-dicarboxamide;-   N-hydroxy-5-methyl-2-(N-phenylsulfamoyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   N-hydroxy-5-phenyl-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   5-benzyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   5-benzoyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   5-(cyclohexanecarbonyl)-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   N-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   N-hydroxy-5-(phenylsulfonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   N8-hydroxy-N5-phenyl-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5,8(6H)-dicarboxamide;-   N-hydroxy-5-(N-phenylsulfamoyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   5-(cyclohexylmethyl)-N-hydroxy-6-oxo-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-8-carboxamide;-   N-hydroxy-5-phenyl-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-8-carboxamide;-   5-benzyl-N-hydroxy-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-8-carboxamide;-   5-benzoyl-N-hydroxy-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-8-carboxamide;-   5-(cyclohexanecarbonyl)-N-hydroxy-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-8-carboxamide;-   N-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-8-carboxamide;-   N-hydroxy-5-(phenylsulfonyl)-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-8-carboxamide;-   N8-hydroxy-N5-phenyl-3,4-dihydro-2H-2,4-methanobenzo[b][1,5]oxazocine-5,8(6H)-dicarboxamide;-   N-hydroxy-5-(N-phenylsulfamoyl)-3,4,5,6-tetrahydro-2H-2,4-methanobenzo[b][1,5]oxazocine-8-carboxamide;-   N-hydroxy-2-methyl-5-phenyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   5-benzyl-N-hydroxy-2-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   5-benzoyl-N-hydroxy-2-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   5-(cyclohexanecarbonyl)-N-hydroxy-2-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   N-hydroxy-2-methyl-5-(tetrahydro-2H-pyran-4-carbonyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;-   N9-hydroxy-5-methyl-N2-phenyl-3,4,5,6-tetrahydrobenzo[f][1,4]diazocine-2,9(1H)-dicarboxamide;    or-   N-hydroxy-2-methyl-5-(N-phenylsulfamoyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide.

In an illustrative embodiment the compound of Formula II is:

-   N-hydroxy-4-phenyl-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-9-carboxamide;-   4-benzyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-9-carboxamide;-   4-benzoyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-9-carboxamide;-   4-(cyclohexanecarbonyl)-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-9-carboxamide;-   N-hydroxy-4-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-9-carboxamide;-   N-hydroxy-4-(phenylsulfonyl)-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-9-carboxamide;-   N9-hydroxy-N4-phenyl-2,3,5,6-tetrahydro-4H-benzo[g][1,4]oxazocine-4,9-dicarboxamide;-   4-(cyclohexylmethyl)-N-hydroxy-5-oxo-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-9-carboxamide;-   N-hydroxy-4-phenyl-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-8-carboxamide;-   4-benzyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-8-carboxamide;-   4-benzoyl-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-8-carboxamide;-   4-(cyclohexanecarbonyl)-N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-8-carboxamide;-   N-hydroxy-4-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-8-carboxamide;-   N-hydroxy-4-(phenylsulfonyl)-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-8-carboxamide;-   N8-hydroxy-N4-phenyl-2,3,5,6-tetrahydro-4H-benzo[g][1,4]oxazocine-4,8-dicarboxamide;    or-   4-(cyclohexylmethyl)-N-hydroxy-5-oxo-3,4,5,6-tetrahydro-2H-benzo[g][1,4]oxazocine-8-carboxamide.

In another embodiment, illustrative compounds of the invention include:

-   N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;-   N-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide;    and-   N-hydroxy-5-(4-methyltetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide.

In another embodiment of the invention, the compounds of Formulae I orII are enantiomers. In some embodiments the compounds are the(S)-enantiomer. In other embodiments the compounds are the(R)-enantiomer. In yet other embodiments, the compounds of Formulae I orII may be (+) or (−) enantiomers.

It should be understood that all isomeric forms are included within thepresent invention, including mixtures thereof. If the compound containsa double bond, the substituent may be in the E or Z configuration. Ifthe compound contains a disubstituted cycloalkyl, the cycloalkylsubstituent may have a cis- or trans configuration. All tautomeric formsare also intended to be included.

Methods of Synthesizing the Disclosed Compounds

The compounds of the present invention may be made by a variety ofmethods, including standard chemistry. Suitable synthetic routes aredepicted in the schemes given below.

The compounds of Formulae I or II may be prepared by methods known inthe art of organic synthesis as set forth in part by the followingsynthetic schemes and examples. In the schemes described below, it iswell understood that protecting groups for sensitive or reactive groupsare employed where necessary in accordance with general principles orchemistry. Protecting groups are manipulated according to standardmethods of organic synthesis (T. W. Greene and P. G. M. Wuts,“Protective Groups in Organic Synthesis”, Third edition, Wiley, New York1999). These groups are removed at a convenient stage of the compoundsynthesis using methods that are readily apparent to those skilled inthe art. The selection processes, as well as the reaction conditions andorder of their execution, shall be consistent with the preparation ofcompounds of Formulae I or II.

Those skilled in the art will recognize if a stereocenter exists in thecompounds of Formulae I or II. Accordingly, the present inventionincludes both possible stereoisomers (unless specified in the synthesis)and includes not only racemic compounds but the individual enantiomersand/or diastereomers as well. When a compound is desired as a singleenantiomer or diastereomer, it may be obtained by stereospecificsynthesis or by resolution of the final product or any convenientintermediate. Resolution of the final product, an intermediate, or astarting material may be affected by any suitable method known in theart. See, for example, “Stereochemistry of Organic Compounds” by E. L.Eliel, S. H. Wilen, and L. N. Mander (Wiley-lnterscience, 1994).

The compounds described herein may be made from commercially availablestarting materials or synthesized using known organic, inorganic, and/orenzymatic processes.

Preparation of Compounds

The compounds of the present invention can be prepared in a number ofways well known to those skilled in the art of organic synthesis. By wayof example, compounds of the present invention can be synthesized usingthe methods described below, together with synthetic methods known inthe art of synthetic organic chemistry, or variations thereon asappreciated by those skilled in the art. These methods include but arenot limited to those methods described below. Compounds of the presentdisclosure can be synthesized by following the steps outlined in GeneralSchemes 1, 2, and 3 which comprise different sequences of assemblingintermediates 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 2m, 2n, 2o,2p, 2q, 2r, 2s, 2t, and 2u. Starting materials are either commerciallyavailable or made by known procedures in the reported literature or asillustrated.

The general way of preparing target molecules of Formula (I) by usingintermediates 2a, 2b, 2c, 2d, 2e, 2f, 2g, and 2h is outlined in GeneralScheme 1. Esterification of Intermediate 2a in an alcohol, e.g.,methanol (MeOH) in the presence of an acid, e.g., sulfuric acid (H₂SO₄)provides Intermediate 2b. Nucleophilc addition of alcohol 2b tointermediate 2c using a base, e.g., potassium carbonate (K₂CO₃) in asolvent, e.g., acetone, provides Intermediate 2d. Deprotection of 2dwith an acid, e.g., trifluoroacetic acid (TFA) in a solvent, e.g.,dichloromethane, and subsequent cyclization in the presence of a base,e.g., LiHMDS provides intermediate 2e. Reduction of the amide linkage in2e with a mild reducing agent, for instance, borane, in the presence ofa solvent, e.g., tetrahydrofuran (THF) provides Intermediate 2f.Addition of the R-L moiety can be achieved via alkylation, reductiveamination, arylation, acylation, sulfonation, or coupling reactions. Forexample, coupling of a carboxylic acid with Intermediate 2f understandard coupling conditions using a coupling reagent, e.g.,1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium3-oxidehexafluoro-phosphate (HATU), orO-benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate(HBTU), and a base, e.g., triethylamine or N,N-diisopropylethylamine(DIPEA), in a solvent, e.g., DMF, provides Intermediate 2g. The coupledproduct 2g can be carbonylated in the presence of a metal catalyst,e.g., [1,1′-bis(diphenylphosphino)ferrocene]dichloro palladium(II) andcarbon monoxide in a solvent, e.g., ethanol to provide Intermediate 2h.Treatment of intermediate 2h with hydroxylamine and a base, e.g.,aqueous sodium hydroxide (NaOH (aq)) in a solvent, e.g., tetrahydrofuranand/or methanol provides compounds of Formula (I).

The general way of preparing target molecules of Formula (I) by usingIntermediates 2b, 2i, 2j, 2k, 2m, 2n, and 2o is outlined in GeneralScheme 2. A secondary alcohol such as that of 2i is activated in thepresence of, for instance, diethyl azodicarboxylate (DEAD) andtriphenylphosphine (PPh₃) and in a solvent, e.g., tetrahydrofuran (THF)and reacted with the hydroxy group of Intermediate 2b to giveIntermediate 2j. Reduction of the ester in 2j with a reducing agent,e.g., lithium aluminum hydride (LAH) in a solvent, e.g., tetrahydrofuran(THF) provides the corresponding alcohol which is converted to a primarybenzyl chloride 2k by treating with thionyl chloride (SOCl₂) in asolvent, e.g., dichloromethane (DCM). An intramolecular nucleophilicsubstitution reaction in the presence of a base, e.g., potassiumcarbonate (K₂CO₃) in a solvent, e.g., dimethylformamide (DMF) providesintermediate 2m. Addition of the R-L moiety can be achieved viaalkylation, reductive amination, arylation, acylation, sulfonation, orcoupling reactions. For example, coupling of a carboxylic acid withIntermediate 2m under standard coupling conditions using a couplingreagent, e.g.,1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium3-oxidehexafluoro-phosphate (HATU), orO-benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate(HBTU), and a base, e.g., triethylamine or N,N-diisopropylethylamine(DIPEA), in a solvent, e.g., DMF, provides Intermediate 2n. The coupledproduct 2n can be carbonylated in the presence of a metal catalyst,e.g., [1,1′-bis(diphenylphosphino)ferrocene]dichloro palladium(II) andcarbon monoxide in a solvent, e.g., methanol to provide Intermediate 2o.Treatment of intermediate 2o with hydroxylamine and a base, e.g.,aqueous sodium hydroxide (NaOH (aq)) in a solvent, e.g., tetrahydrofuranand/or methanol provides compounds of Formula (I).

The general way of preparing target molecules of Formula (I) by usingIntermediates 2p, 2q, 2r, 2s, 2t, and 2u is outlined in General Scheme3. Reductive amination of the aldehyde of 2q with the amino group of 2pin the presence of an acid, e.g., acetic acid using a reducing agent,e.g., sodium cyanoborohydride (NaBH₃CN) in a solvent, e.g.,dichloromethane (DCM) followed by protection of the resulting amine witha protecting group, e.g., benzyl chloroformate, in the presence of abase, e.g., potassium carbonate (K₂CO₃), provides Intermediate 2r.Selective depotection of the tert-butoxycarbonyl (Boc) protecting groupof 2r in the presence of an acid, e.g., trifluoroacetic acid (TFA), in asolvent, e.g., dichloromethane (DCM) followed by treatment with a base,e.g., potassium carbonate (K₂CO₃), completes an intramolecularnucleophilc substitution reaction to form a bicycle. Deprotection of thecarboxybenzyl protecting group under an atmosphere of hydrogen withcatalytic palladium on carbon affords Intermediate 2s. The deprotectedproduct 2s can be carbonylated in the presence of a metal catalyst,e.g., [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II)-dichloromethane adduct and carbon monoxide in a solvent,e.g., methanol to provide Intermediate 2t. Addition of the R-L moietycan be achieved via alkylation, reductive amination, arylation,acylation, sulfonation, or coupling reactions. For example, coupling ofa carboxylic acid with Intermediate 2t under standard couplingconditions using a coupling reagent, e.g.,1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium3-oxidehexafluoro-phosphate (HATU), orO-benzotriazole-N,N,N′,N′-tetramethyl-uronium-hexafluoro-phosphate(HBTU), and a base, e.g., triethylamine or N,N-diisopropylethylamine(DIPEA), in a solvent, e.g., DMF, provides Intermediate 2u. Treatment ofintermediate 2u with hydroxylamine and a base, e.g., aqueous sodiumhydroxide (NaOH (aq)) in a solvent, e.g., tetrahydrofuran and/ormethanol provides compounds of Formula (I).

Methods of Using the Disclosed Compounds

Another aspect of the invention relates to a method of treating adisease associated with HDAC, e.g., HDAC6, modulation in a subject inneed thereof. The method involves administering to a patient in need oftreatment for diseases or disorders associated with HDAC, e.g., HDAC6,modulation an effective amount of a compound of Formula I. In anembodiment, the disease can be, but is not limited to, cancer,neurodegenerative disease, neurodevelopmental disease, inflammatory orautoimmune disease, infection, metabolic disease, hematologic disease,or cardiovascular disease.

Another aspect of the invention is directed to a method of inhibiting anHDAC, e.g., HDAC6. The method involves administering to a patient inneed thereof an effective amount of Formula I.

The present invention relates to compositions capable of modulating theactivity of (e.g., inhibiting) HDACs, for instance HDAC6. The presentinvention also relates to the therapeutic use of such compounds.

One therapeutic use of the compounds of the present invention is totreat proliferative diseases or disorders such as cancer. Cancer can beunderstood as abnormal or unregulated cell growth within a patient andcan include but is not limited to lung cancer, ovarian cancer, breastcancer, prostate cancer, pancreatic cancer, hepatocellular cancer, renalcancer and leukemias such as acute myeloid leukemia and acutelymphoblastic leukemia. Additional cancer types include T-cell lymphoma(e.g., cutaneous T-cell lymphoma, peripheral T-cell lymphoma), andmultiple myeloma.

One therapeutic use of the compounds of the present invention is totreat neurological diseases or disorders or neurodegeneration.Neurological disorders are understood as disorders of the nervous system(e.g., the brain and spinal cord). Neurological disorders orneurodegenerative diseases can include but are not limited to epilepsy,attention deficit disorder (ADD), Alzheimer's disease, Parkinson'sDisease, Huntington's Disease, amyotrophic lateral sclerosis, spinalmuscular atrophy, essential tremor, central nervous system trauma causedby tissue injury, oxidative stress-induced neuronal or axomaldegeneration, and multiple sclerosis.

Another therapeutic use of the compounds of the present invention is totreat neurodevelopmental disorders. Neurodevelopmental disorders caninclude, but are not limited to, Rett syndrome.

Another therapeutic use of the compounds of the present invention isalso to treat inflammatory diseases or disorders. Inflammation can beunderstood as a host's response to an initial injury or infection.Symptoms of inflammation can include but are not limited to redness,swelling, pain, heat and loss of function. Inflammation may be caused bythe upregulation of pro-inflammatory cytokines such as IL-10, andincreased expression of the FOXP3 transcription factor.

Another therapeutic use of the compounds of the present invention isalso to treat autoimmune diseases or disorders. Autoimmune disorders areunderstood as disorders wherein a host's own immune system responds totissues and substances occurring naturally in the host's body.Autoimmune diseases can include but are not limited to Rheumatoidarthritis, spondylitis arthritis, psoriatic arthritis, multiplesclerosis, systemic lupus erythematosus, inflammatory bowel disease,graft versus host disease, transplant rejection, fibrotic disease,Crohn's Disease, type-1 diabetes, Eczema, and psoriasis.

Another therapeutic use of the compounds of the present invention isalso to treat infectious diseases or disorders. Infections or infectiousdiseases are caused by the invasion of a foreign pathogen. The infectionmay be caused by, for instance, a bacteria, a fungus, or virus. Forexample, a bacterial infection may be caused by a E. coli.

Yet another therapeutic use of the compounds of the present invention isalso to treat metabolic diseases or disorders. Metabolic diseases can becharacterized as abnormalities in the way that a subject stores energy.Metabolic disorders can include but are not limited to metabolicsyndrome, diabetes, obesity, high blood pressure, and heart failure.

Yet another therapeutic use of the compounds of the present invention isalso to treat hematologic disorders. Hematologic diseases primarilyaffect the blood. Hematologic disorders can include but are not limitedto anemia, lymphoma, and leukemia.

Yet another therapeutic use of the compounds of the present invention isalso to treat cardiovascular diseases or disorders. Cardiovasculardiseases affect the heart and blood vessels of a patient. Exemplaryconditions include but are not limited to cardiovascular stress,pressure overload, chronic ischemia, infarction-reperfusion injury,hypertension, atherosclerosis, peripheral artery disease, and heartfailure.

The disclosed compound can be administered in effective amounts to treator prevent a disorder and/or prevent the development thereof insubjects.

Administration of the disclosed compounds can be accomplished via anymode of administration for therapeutic agents. These modes includesystemic or local administration such as oral, nasal, parenteral,transdermal, subcutaneous, vaginal, buccal, rectal or topicaladministration modes.

Depending on the intended mode of administration, the disclosedcompositions can be in solid, semi-solid or liquid dosage form, such as,for example, injectables, tablets, suppositories, pills, time-releasecapsules, elixirs, tinctures, emulsions, syrups, powders, liquids,suspensions, or the like, sometimes in unit dosages and consistent withconventional pharmaceutical practices. Likewise, they can also beadministered in intravenous (both bolus and infusion), intraperitoneal,subcutaneous or intramuscular form, all using forms well known to thoseskilled in the pharmaceutical arts.

Illustrative pharmaceutical compositions are tablets and gelatincapsules comprising a Compound of the Invention and a pharmaceuticallyacceptable carrier, such as a) a diluent, e.g., purified water,triglyceride oils, such as hydrogenated or partially hydrogenatedvegetable oil, or mixtures thereof, corn oil, olive oil, sunflower oil,safflower oil, fish oils, such as EPA or DHA, or their esters ortriglycerides or mixtures thereof, omega-3 fatty acids or derivativesthereof, lactose, dextrose, sucrose, mannitol, sorbitol, cellulose,sodium, saccharin, glucose and/or glycine; b) a lubricant, e.g., silica,talcum, stearic acid, its magnesium or calcium salt, sodium oleate,sodium stearate, magnesium stearate, sodium benzoate, sodium acetate,sodium chloride and/or polyethylene glycol; for tablets also; c) abinder, e.g., magnesium aluminum silicate, starch paste, gelatin,tragacanth, methylcellulose, sodium carboxymethylcellulose, magnesiumcarbonate, natural sugars such as glucose or beta-lactose, cornsweeteners, natural and synthetic gums such as acacia, tragacanth orsodium alginate, waxes and/or polyvinylpyrrolidone, if desired; d) adisintegrant, e.g., starches, agar, methyl cellulose, bentonite, xanthangum, algiic acid or its sodium salt, or effervescent mixtures; e)absorbent, colorant, flavorant and sweetener; f) an emulsifier ordispersing agent, such as Tween 80, Labrasol, HPMC, DOSS, caproyl 909,labrafac, labrafil, peceol, transcutol, capmul MCM, capmul PG-12, captex355, gelucire, vitamin E TGPS or other acceptable emulsifier; and/or g)an agent that enhances absorption of the compound such as cyclodextrin,hydroxypropyl-cyclodextrin, PEG400, PEG200.

Liquid, particularly injectable, compositions can, for example, beprepared by dissolution, dispersion, etc. For example, the disclosedcompound is dissolved in or mixed with a pharmaceutically acceptablesolvent such as, for example, water, saline, aqueous dextrose, glycerol,ethanol, and the like, to thereby form an injectable isotonic solutionor suspension. Proteins such as albumin, chylomicron particles, or serumproteins can be used to solubilize the disclosed compounds.

The disclosed compounds can be also formulated as a suppository that canbe prepared from fatty emulsions or suspensions; using polyalkyleneglycols such as propylene glycol, as the carrier.

The disclosed compounds can also be administered in the form of liposomedelivery systems, such as small unilamellar vesicles, large unilamellarvesicles and multilamellar vesicles. Liposomes can be formed from avariety of phospholipids, containing cholesterol, stearylamine orphosphatidylcholines. In some embodiments, a film of lipid components ishydrated with an aqueous solution of drug to a form lipid layerencapsulating the drug, as described in U.S. Pat. No. 5,262,564.

Disclosed compounds can also be delivered by the use of monoclonalantibodies as individual carriers to which the disclosed compounds arecoupled. The disclosed compounds can also be coupled with solublepolymers as targetable drug carriers. Such polymers can includepolyvinylpyrrolidone, pyran copolymer,polyhydroxypropylmethacrylamide-phenol,polyhydroxyethylaspanamidephenol, or polyethyleneoxidepolylysinesubstituted with palmitoyl residues. Furthermore, the disclosedcompounds can be coupled to a class of biodegradable polymers useful inachieving controlled release of a drug, for example, polylactic acid,polyepsilon caprolactone, polyhydroxy butyric acid, polyorthoesters,polyacetals, polydihydropyrans, polycyanoacrylates and cross-linked oramphipathic block copolymers of hydrogels. In one embodiment, disclosedcompounds are not covalently bound to a polymer, e.g., a polycarboxylicacid polymer, or a polyacrylate.

Parental injectable administration is generally used for subcutaneous,intramuscular or intravenous injections and infusions. Injectables canbe prepared in conventional forms, either as liquid solutions orsuspensions or solid forms suitable for dissolving in liquid prior toinjection.

Another aspect of the invention relates to a pharmaceutical compositioncomprising a compound of Formulae I or II and a pharmaceuticallyacceptable carrier. The pharmaceutically acceptable carrier can furtherinclude an excipient, diluent, or surfactant.

Compositions can be prepared according to conventional mixing,granulating or coating methods, respectively, and the presentpharmaceutical compositions can contain from about 0.1% to about 99%,from about 5% to about 90%, or from about 1% to about 20% of thedisclosed compound by weight or volume.

The dosage regimen utilizing the disclosed compound is selected inaccordance with a variety of factors including type, species, age,weight, sex and medical condition of the patient; the severity of thecondition to be treated; the route of administration; the renal orhepatic function of the patient; and the particular disclosed compoundemployed. A physician or veterinarian of ordinary skill in the art canreadily determine and prescribe the effective amount of the drugrequired to prevent, counter or arrest the progress of the condition.

Effective dosage amounts of the disclosed compounds, when used for theindicated effects, range from about 0.5 mg to about 5000 mg of thedisclosed compound as needed to treat the condition. Compositions for invivo or in vitro use can contain about 0.5, 5, 20, 50, 75, 100, 150,250, 500, 750, 1000, 1250, 2500, 3500, or 5000 mg of the disclosedcompound, or, in a range of from one amount to another amount in thelist of doses. In one embodiment, the compositions are in the form of atablet that can be scored.

Without wishing to be bound by any particular theory, the compounds ofthe present invention can inhibit HDACs such as HDAC6 by interactingwith the zinc (Zn²⁺) ion in the protein's active site via the hydroxamicacid group bound to the aromatic ring of the compound. The binding canprevent the zinc ion from interacting with its natural substrates, thusinhibiting the enzyme.

EXAMPLES

The disclosure is further illustrated by the following examples andsynthesis examples, which are not to be construed as limiting thisdisclosure in scope or spirit to the specific procedures hereindescribed. It is to be understood that the examples are provided toillustrate certain embodiments and that no limitation to the scope ofthe disclosure is intended thereby. It is to be further understood thatresort may be had to various other embodiments, modifications, andequivalents thereof which may suggest themselves to those skilled in theart without departing from the spirit of the present disclosure and/orscope of the appended claims.

The present invention includes a number of unique features andadvantages compared with other inhibitors of HDAC enzymes, in particularHDAC6. For instance, the present invention features a unique class ofsmall molecule therapeutic agents of Formulae I or II. The compoundswere designed by using crystal structure information of HDACligand-protein complexes as well as advanced computational chemistrytools. These techniques led to the development of new chemical scaffoldsthat were iteratively refined to optimize key recognition featuresbetween the ligand and receptor known to be necessary for potency.

Definitions used in the following examples and elsewhere herein are:

-   BH₃: borane-   DMSO: dimethylsulfoxide-   EtOH: ethanol-   H₂SO₄: sulfuric acid-   KCl: potassium chloride-   LiHMDS: lithium bis(trimethylsilyl)amide-   CH2Cl2: methylene chloride, dichloromethane-   CO: carbon monoxide-   DIEA: diisopropylethylamine-   DMF: N,N-dimethylformamide-   EtOAc: ethyl acetate-   H2O: water-   HCl: hydrochloric acid-   HATU:    1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium    3-oxid hexafluorophosphate-   MeCN: acetonitrile-   MeOH: methanol-   NaHCO₃: sodium bicarbonate-   NaOH: sodium hydroxide-   Pd(dppf)Cl₂.CH₂Cl₂: [1,1′-bis(diphenylphosphino)ferrocene]dichloro    palladium(II)-dichloromethane adduct-   pet. ether: petroleum ether-   TFA: trifluoroacetic acid-   THF: tetrahydrofuran

Example 1—Preparation ofN-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide

Step-1: Methyl 4-bromo-2-hydroxybenzoate

4-Bromo-2-hydroxybenzoic acid (10.0 g, 46.08 mmol, 1.0 equiv) and MeOH(50 mL) were placed in a 250-mL round-bottom flask. This was followed bythe addition of sulfuric acid (20 mL) dropwise with stirring at 0° C.The resulting solution was stirred for 16 h at 65° C. in an oil bath,then concentrated under vacuum. The residue was dissolved in EtOAc (300mL) and washed with H₂O (3×100 mL) and aq. 2N NaHCO₃ (3×100 mL). Theorganic layer was dried over anhydrous sodium sulfate, filtered,concentrated, and purified by silica gel chromatography (EtOAc/pet.ether, 1:20) to afford methyl 4-bromo-2-hydroxybenzoate as a lightyellow solid (7.80 g, 73% yield). MS: (ES, m/z): 231 [M+H]+.

Step-2: Methyl 4-bromo-2-(3-(tert-butoxycarbonylamino)propoxy)benzoate

Methyl 4-bromo-2-hydroxybenzoate (3.00 g, 12.98 mmol, 1.0 equiv) inpropan-2-one (15 mL), potassium carbonate (5.40 g, 39.07 mmol, 3.0equiv) and tert-butyl N-(3-bromopropyl)carbamate (3.7 g, 15.54 mmol,1.20 equiv) were place in a 100-mL round-bottom flask. The resultingmixture was stirred for 16 h at 60° C. in an oil bath, then concentratedunder vacuum. The residue was dissolved in EtOAc (200 mL) and washedwith H₂O (3×100 mL). The organic layer was dried over anhydrous sodiumsulfate, filtered, and concentrated to afford methyl4-bromo-2-(3-(tert-butoxycarbonylamino)propoxy)benzoate as a lightyellow oil (5.89 g). This material was used without furtherpurification. MS: (ES, m/z): 388 [M+H]⁺.

Step-3: Methyl 2-(3-aminopropoxy)-4-bromobenzoate

Methyl 4-bromo-2-(3-(tert-butoxycarbonylamino)propoxy)benzoate (3.0 g,7.73 mmol) and dichloromethane (10 mL) were placed in a 100-mLround-bottom flask. This was followed by the addition of trifluoroaceticacid (10 mL) dropwise with stirring at 0° C. The resulting solution wasstirred for 3 h at room temperature, then concentrated under vacuum. Theresidue was dissolved in H₂O (150 mL) and the pH of the solution wasadjusted to 8 with aq. 4N NaOH. The resulting solution was extractedwith EtOAc (3×100 mL). The organic layer was dried over anhydrous sodiumsulfate, filtered, and concentrated under vacuum to afford methyl2-(3-aminopropoxy)-4-bromobenzoate as a yellow oil (1.57 g, 71% yield).MS: (ES, m/z): 288 [M+H]⁺.

Step-4: 9-Bromo-2,3,4,5-tetrahydro-6H-benzo[b][1,5]oxazocin-6-one

Methyl 2-(3-aminopropoxy)-4-bromobenzoate (1.57 g, 5.45 mmol, 1.0 equiv)and THF (1.5 L) were placed in a 3-L 3-necked round-bottom flask thathas been purged and maintained with an inert atmosphere of nitrogen.This was followed by the addition of a solution of LiHMDS (1M, 27 mL,5.0 equiv) in THF (31 mL) dropwise with stirring at −5° C. The resultingsolution was stirred for 16 h at room temperature. The reaction was thenquenched by the addition of ethanol (30 mL) and concentrated undervacuum. The residue was dissolved in EtOAc (300 mL) and washed with H₂O(3×100 mL). The organic layer was dried over anhydrous sodium sulfate,filtered, concentrated, and purified by silica gel chromatography(MeOH/CH₂Cl₂, 1:20) to afford9-bromo-2,3,4,5-tetrahydro-6H-benzo[b][1,5]oxazocin-6-one as a red solid(300 mg, 21% yield). MS: (ES, m/z): 256 [M+H]⁺.

Step-5: 9-Bromo-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine

9-Bromo-2,3,4,5-tetrahydro-6H-benzo[b][1,5]oxazocin-6-one (300 mg, 1.17mmol, 1.0 equiv) and THF (10 mL) were placed in a 50-mL round-bottomflask. This was followed by the addition of a solution ofborane-tetrahydrofuran complex (1M, 11.80 mL) dropwise with stirring at0° C. The resulting solution was stirred for 16 h at 60° C. in an oilbath. The reaction was then cooled to 0° C. and quenched by the additionof MeOH (5 mL) at 0° C. Then 6M HCl (3 mL) was added. The resultingsolution was stirred for 16 h at room temperature. Then the pH of thereaction was adjusted to 8 with aq. 4N NaOH. The resulting mixture wasconcentrated under vacuum. The residue was dissolved in EtOAc (100 mL)and washed with H₂O (3×30 mL). The organic layer was dried overanhydrous sodium sulfate, filtered, and concentrated to afford9-bromo-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine as a light yellowsolid (250 mg, 88% yield). MS: (ES, m/z): 242 [M+H]+.

Step-6: tert-Butyl9-bromo-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5(6H)-carboxylate

9-Bromo-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine (140 mg, 0.58 mmol,1.0 equiv), dichloromethane (5 mL), triethylamine (120 mg, 1.19 mmol,2.0 equiv) and di-tert-butyl oxalate (260 mg, 1.29 mmol, 2.0 equiv) wereplaced in a 50-mL round-bottom flask. The resulting solution was stirredfor 16 h at room temperature. The resulting mixture was concentrated andpurified by silica gel chromatography (EtOAc/pet. ether, 1:3) to affordtert-butyl9-bromo-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5(6H)-carboxylate as alight yellow solid (130 mg, 66% yield). MS: (ES, m/z): 342 [M+H]⁺.

Step-7: 5-(tert-Butyl)9-ethyl-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5,9(6H)-dicarboxylate

tert-Butyl9-bromo-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5(6H)-carboxylate (130 mg,0.38 mmol, 1.0 equiv) in ethanol (10 mL), triethylamine (115 mg, 1.14mmol, 3.0 equiv) and Pd(dppf)Cl₂.CH₂Cl₂ (27 mg, 0.04 mmol, 0.10 equiv)were placed in a 20-mL pressure tank reactor and CO(g) (50 atm) wasintroduced. The resulting mixture was stirred for 16 h at 120° C. in anoil bath and then concentrated under vacuum. The residue was dissolvedin EtOAc (50 mL) and washed with H₂O (2×20 mL). The organic layer wasdried over anhydrous sodium sulfate, filtered, concentrated, andpurified by silica gel chromatography (EtOAc/pet. ether, 1:4) to afford5-(tert-butyl)9-ethyl-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5,9(6H)-dicarboxylate aslight yellow oil (90 mg, 71% yield). MS: (ES, m/z): 336 [M+H]⁺.

Step-8: Ethyl 3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxylate

5-(tert-Butyl)9-ethyl-3,4-dihydro-2H-benzo[b][1,5]oxazocine-5,9(6H)-dicarboxylate (90mg, 0.27 mmol, 1.0 equiv) and dichloromethane (5 mL) were placed in a50-mL round-bottom flask. This was followed by the addition oftrifluoroacetic acid (5 mL) dropwise with stirring at 0° C. Theresulting solution was stirred for 16 h at room temperature, thenconcentrated under vacuum. The residue was dissolved in H₂O (50 mL). ThepH of the solution was adjusted to 8 with aq. 4N NaOH. The resultingsolution was extracted with EtOAc (3×20 mL). The organic layer was driedover anhydrous sodium sulfate, filtered, and concentrated to affordethyl 3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxylate aslight yellow oil (60 mg, 95% yield). MS: (ES, m/z): 236 [M+H]⁺.

Step-9:N-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide

Ethyl 3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxylate (60 mg,0.26 mmol, 1.0 equiv) and THF/MeOH (4:1, 1.5 mL) were placed in a 8-mLvial. Then solutions of hydroxylamine (50% in water, 0.51 mL, 30 equiv)and aq. 1M NaOH (0.51 mL, 2.0 equiv) were added at the same time. Theresulting solution was stirred for 2 h at room temperature. The crudeproduct was purified by Prep-HPLC (Column: XBridge BEH C18 OBD Prep 5 m19×250 mm; Mobile Phase A: Water/0.05% TFA; Mobile Phase B: MeCN; Flowrate: 20 mL/min; Gradient: 2% B to 8% B in 6 min; Detector: UV 254, 220nm). 1N HCl (0.26 mL, 1.0 equiv) was added to the product fractions andthe mixture was lyophilized with 2N HCl (1 mL) to afford thehydrochloride salt ofN-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide asa off-white solid (23.7 mg, 36% yield). ¹H-NMR (400 MHz, DMSO-d₆) δ(ppm): 11.35 (s, 1H), 9.42 (br s, 2H), 9.14 (br s, 1H), 7.61-7.54 (m,3H), 4.17-4.15 (t, J=4.8 Hz, 4H), 3.13 (s, 2H), 1.82 (s, 2H). MS: (ES,m/z): 223 [M−HCl+H]⁺.

Example 2—Preparation ofN-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide

Step-1:9-Bromo-3,4-dihydro-2H-benzo[b][1,5]oxazocin-5(6H)-yl)(tetrahydro-2H-pyran-4-yl)methanone

9-Bromo-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine (250 mg, 1.03 mmol,1.0 equiv) and DMF (3 mL) were placed in a 25-mL round-bottom flask.This was followed by the addition of oxane-4-carboxylic acid (162 mg,1.24 mmol, 1.2 equiv), HATU (471 mg, 1.95 mmol, 1.2 equiv) and DIEA (402mg, 3.11 mmol, 3.0 equiv) at 0° C. The resulting solution was stirredfor 16 h at room temperature. The resulting solution was diluted withEtOAc (15 mL) and washed with H₂O (5×50 mL). The organic layer was driedover anhydrous sodium sulfate, filtered, concentrated, and purified bysilica gel chromatography (MeOH/CH₂Cl₂, 1:25) to afford9-bromo-3,4-dihydro-2H-benzo[b][1,5]oxazocin-5(6H)-yl)(tetrahydro-2H-pyran-4-yl)methanoneas light yellow oil (200 mg, 55% yield). MS: (ES, m/z): 354 [M+H]⁺.

Step-2: Ethyl5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxylate

9-Bromo-3,4-dihydro-2H-benzo[b][1,5]oxazocin-5(6H)-yl)(tetrahydro-2H-pyran-4-yl)methanone(170 mg, 0.48 mmol, 1.0 equiv) in EtOH (15 mL), triethylamine (242 mg,2.39 mmol, 3.0 equiv) and Pd(dppf)Cl₂.CH₂Cl₂ (36 mg, 0.05 mmol, 0.10equiv) were place in a 20-mL pressure tank reactor and CO(g) (50 atm)was introduced. The resulting mixture was stirred for 16 h at 120° C. inan oil bath. The resulting mixture was concentrated and purified bysilica gel chromatography (MeOH/CH₂Cl₂, 1:25) to afford ethyl5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxylateas light brown oil (160 mg, 96% yield). MS: (ES, m/z): 348 [M+H]⁺.

Step-3:N-Hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide

Ethyl5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxylate(85 mg, 0.24 mmol, 1.0 equiv) and THF/MeOH (4:1, 1.5 mL) were placed ina 8-mL vial. Then solutions of hydroxylamine (50% in water, 0.48 mL, 30equiv) and aq. 1N NaOH (0.49 mL, 2.0 equiv) were added at the same time.The resulting solution was stirred for 2 h at room temperature. Thecrude product was purified by Prep-HPLC (Column: XBridge C18 OBD Prep 5m 19×150 mm; Mobile Phase A: Water/0.1% Formic Acid; Mobile Phase B:MeCN; Flow rate: 25 mL/min; Gradient: 5% B to 43% B in 7 min; Detector:UV 254, 220 nm) to affordN-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamideas a pink solid (12.7 mg, 16% yield). ¹H-NMR (400 MHz, DMSO-d₆) δ (ppm):11.10 (br s, 1H), 9.05 (br s, 1H), 7.53-7.39 (m, 3H), 4.71-4.48 (d, 2H),4.16-4.03 (m, 2H), 3.82-3.67 (m, 4H), 3.37-3.30 (m, 2H), 3.00-2.76 (m,1H), 1.76-1.72 (m, 2H), 1.61-1.25 (m, 4H). MS: (ES, m/z): 335 [M+H]⁺.

TABLE 1 The following compound was prepared by the method of Example 2.Found Structure M + H ¹H-NMR (400 MHz, DMSO-d₆) δ (ppm)

(ES, m/z): 349 [M + H]⁺ 11.16 (br s, 1H), 9.05 (br s, 1H), 7.49-7.44 (m,3H), 4.56 (s, 2H), 4.17-4.14 (t, J = 5.6 Hz, 2H), 3.82-3.80 (t, J = 4Hz, 2H), 3.60-3.55 (m, 2H), 3.40-3.36 (t J = 8.8 Hz, 2H), 1.97-1.94 (d,J = 14.4 Hz, 2H), 1.65 (s, 2H), 1.46-1.40 (m, 2H), 1.22 (s, 3H).

Example 3—In Vitro Histone Deacetylase Assay

The enzymatic HDAC6 assay was performed using electrophoretic mobilityshift assay. Full length human recombinant HDAC6 protein were expressedin baculoviral system and purified by affinity chromatography. Theenzymatic reactions were assembled in 384 well plates in a total volumeof 25 μL in a reaction buffer composing: 100 mM HEPES, pH7.5, 25 mM KCl,0.1% bovine serum albumin, 0.01% Triton X-100, 1% DMSO (from compounds)2 μM of the fluorescently labeled peptide substrate and enzyme. Theenzyme was added at a final concentration of 1 nM. The peptide substrateRHKK(Ac)-NH2 was used. The compounds were tested at 12 concentrationsspaced by 3× dilution intervals. Negative control samples (0%-inhibitionin the absence of inhibitor) and positive control samples(100%-inhibition) were assembled in replicates of four in each assayplate. The reactions were incubated at 25° C. and quenched by theaddition of 45 μL of termination buffer (100 mM HEPES, pH 7.5, 0.01%Triton X-100, 0.05% SDS).

The terminated assay plates were analyzed on LabChip® 3000 microfluidicelectrophoresis instrument (Perkin Elmer/Caliper Life Sciences). Thefluorescence intensity of the electrophoretically separatedde-acetylated product and substrate peptide were measured. Activity ineach sample was determined as the product to sum ratio (PSR): P/(S+P),where P is the peak height of the product peptide and S is the peakheight of the substrate peptide. Percent inhibition (Pinh) wasdetermined using the following equation:

Pinh=(PSRO %−PSRinh)/(PSRO %−PSR100%)*100, where PSRinh is the productsum ratio in the presence of inhibitor, PSRO % is the average productsum ration in the absence of inhibitor and PSR100% is the averageproduct sum ratio in 100%-inhibition control samples. The IC50 values ofinhibitors are determined by fitting the %-inhibition curves with 4parameter dose-response model using XLfit 4 software.

As set forth in Table 2, below, IC₅₀ values are defined as follows:IC50≤0.1 μM (+++); IC50>0.1 μM and ≤0.5 μM (++); IC50>0.5 μM (+).

TABLE 2 Inhibitory Concentration (IC50) Values for RepresentativeCompounds against HDAC6. Activity NAME RangeN-hydroxy-3,4,5,6-tetrahydro-2H-benzo[b][1,5]oxazocine-9- + carboxamideN-hydroxy-5-(tetrahydro-2H-pyran-4-carbonyl)-3,4,5,6- ++tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamideN-hydroxy-5-(4-methyltetrahydro-2H-pyran-4-carbonyl)-3,4,5,6- +++tetrahydro-2H-benzo[b][1,5]oxazocine-9-carboxamide

EQUIVALENTS

While the present invention has been described in conjunction with thespecific embodiments set forth above, many alternatives, modificationsand other variations thereof will be apparent to those of ordinary skillin the art. All such alternatives, modifications and variations areintended to fall within the spirit and scope of the present invention.

1-36. (canceled)
 37. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein: X¹ is CR¹R²; X²is NR³; X³, X⁴, and X⁵ are each CR¹R²; Y¹ and Y⁴ are each independentlyN or CR¹; Y² and Y³ are each independently N or CR¹ when not bonded to—C(O)NHOH and Y² and Y³ are C when bonded to —C(O)NHOH; L is a bond,—(CR¹R²)_(n)—, —C(O)—, —C(O)O—, —C(O)NR³—, —S(O)₂—, —S(O)₂NR³—, —S(O)—,—S(O)NR³—, —C(O)(CR¹R²)_(n)O—, or —C(O)(CR¹R²)_(n)—; R is independently,and at each occurrence, —H, —C₁-C₆alkyl, —C₂-C₆alkenyl,—C₄-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl, —C₅-C₁₂spirocyclyl,heterocyclyl, spiroheterocyclyl, aryl, or heteroaryl containing 1-5heteroatoms selected from N, S, P, or O, wherein each alkyl, alkenyl,cycloalkenyl, alkynyl, cycloalkyl, spirocyclyl, heterocyclyl,spiroheterocyclyl, aryl, or heteroaryl is optionally substituted withone or more substituents selected from —OH, halogen, oxo, —NO₂, —CN,—R¹, —R², —OR³, —NHR³, —NR³R⁴, —S(O)₂NR³R⁴, —S(O)₂R¹, —C(O)R¹, —CO₂R¹,—NR³S(O)₂R¹, —S(O)R¹, —S(O)NR³R⁴, —NR³S(O)R¹, heterocyclyl, aryl, andheteroaryl, with the proviso that when L is —C(O)— the spiroheterocyclylis not bound to L via a nitrogen atom; R¹ and R² are independently, andat each occurrence, —H, R³, R⁴, —C₁-C₆alkyl, —C₂-C₆alkenyl,—C₄-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl, heterocyclyl, aryl,heteroaryl containing 1-5 heteroatoms selected from N, S, P, or O, —OH,halogen, —NO₂, —CN, —NHC₁-C₆alkyl, —N(C₁-C₆alkyl)₂,—S(O)₂N(C₁-C₆alkyl)₂, —N(C₁-C₆alkyl)S(O)₂R⁵, —S(O)₂(C₁-C₆alkyl),—(C₁-C₆alkyl)S(O)₂R⁵, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)S(O)₂C₁-C₆alkyl, or (CHR⁵)_(n)NR³R⁴, wherein each alkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl, aryl, orheteroaryl is optionally substituted with one or more substituentsselected from —OH, halogen, —NO₂, oxo, —CN, —R⁵, —OR³, —NHR³, —NR³R⁴,—S(O)₂N(R³)₂, —S(O)₂R⁵, —C(O)R⁵, —CO₂R⁵, —NR³S(O)₂R⁵, —S(O)R⁵,—S(O)NR³R⁴, —NR³S(O)R⁵, heterocyclyl, aryl, and heteroaryl containing1-5 heteroatoms selected from N, S, P, or O; R³ and R⁴ areindependently, and at each occurrence, —H, —C₁-C₆alkyl, —C₂-C₆alkenyl,—C₄-C₈cycloalkenyl, —C₂-C₆alkynyl, —C₃-C₈cycloalkyl, heterocyclyl, aryl,heteroaryl containing 1-5 heteroatoms selected from N, S, P, or O,—S(O)₂N(C₁-C₆alkyl)₂, —S(O)₂(C₁-C₆alkyl), —(C₁-C₆alkyl)S(O)₂R⁵,—C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl, and —(CHR⁵)_(n)N(C₁-C₆alkyl)₂, whereineach alkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkyl, heterocyclyl,aryl, and heteroaryl is optionally substituted with one or moresubstituents selected from —OH, halogen, —NO₂, oxo, —CN, —R⁵,—O(C₁-C₆)alkyl, —NH(C₁-C₆)alkyl, —N(C₁-C₆alkyl)₂, —S(O)₂N(C₁-C₆alkyl)₂,—S(O)₂NHC₁-C₆alkyl, —C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl,—N(C₁-C₆alkyl)S(O)₂C₁-C₆alkyl, —S(O)R⁵, —S(O)N(C₁-C₆alkyl)₂,—N(C₁-C₆alkyl)S(O)R⁵, heterocyclyl, aryl, and heteroaryl containing 1-5heteroatoms selected from N, S, P, or O; R⁵ is independently, and ateach occurrence, —H, —C₁-C₆alkyl, —C₂-C₆alkenyl, —C₄-C₈cycloalkenyl,—C₂-C₆alkynyl, —C₃-C₈cycloalkyl, heterocyclyl, aryl, heteroaryl, —OH,halogen, —NO₂, —CN, —NHC₁-C₆alkyl, —N(C₁-C₆alkyl)₂,—S(O)₂NH(C₁-C₆alkyl), —S(O)₂N(C₁-C₆alkyl)₂, —S(O)₂C₁-C₆alkyl,—C(O)C₁-C₆alkyl, —CO₂C₁-C₆alkyl, —N(C₁-C₆alkyl)SO₂C₁-C₆alkyl,—S(O)(C₁-C₆alkyl), —S(O)N(C₁-C₆alkyl)₂, —N(C₁-C₆alkyl)S(O)(C₁-C₆alkyl),or (CH₂)_(n)N(C₁-C₆alkyl)₂; and n is independently, and at eachoccurrence, an integer from 0 to
 6. 38. The compound of claim 37,wherein X¹, X³, X⁴, and X⁵ are each CH₂.
 39. The compound of claim 37,wherein the compound is of the Formula IA:

or a pharmaceutically acceptable salt thereof.
 40. The compound of claim37, wherein the compound is of the Formula IB:

or a pharmaceutically acceptable salt thereof.
 41. The compound of claim37 selected from:N-hydroxy-5-methyl-2-phenyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;2-benzyl-N-hydroxy-5-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;2-benzoyl-N-hydroxy-5-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;2-(cyclohexanecarbonyl)-N-hydroxy-5-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;N-hydroxy-5-methyl-2-(tetrahydro-2H-pyran-4-carbonyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;N8-hydroxy-5-methyl-N2-phenyl-3,4,5,6-tetrahydrobenzo[f][1,4]diazocine-2,8(1H)-dicarboxamide;N-hydroxy-5-methyl-2-(N-phenylsulfamoyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;N-hydroxy-2-methyl-5-phenyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;5-benzyl-N-hydroxy-2-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;5-benzoyl-N-hydroxy-2-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;5-(cyclohexanecarbonyl)-N-hydroxy-2-methyl-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;N-hydroxy-2-methyl-5-(tetrahydro-2H-pyran-4-carbonyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide;N9-hydroxy-5-methyl-N2-phenyl-3,4,5,6-tetrahydrobenzo[f][1,4]diazocine-2,9(1H)-dicarboxamide;orN-hydroxy-2-methyl-5-(N-phenylsulfamoyl)-1,2,3,4,5,6-hexahydrobenzo[f][1,4]diazocine-8-carboxamide.42. A pharmaceutical composition comprising a compound of claim 37 and apharmaceutically acceptable carrier.
 43. The compound of claim 37,wherein Y¹, Y³, and Y⁴ are each CR¹ and Y² is C.
 44. The compound ofclaim 37, wherein Y¹, Y², and Y⁴ are each CR¹ and Y³ is C.
 45. Thecompound of claim 37, wherein X² is N(CH₃).
 46. The compound of claim45, wherein R is —C₃-C₈cycloalkyl, heterocyclyl, or aryl.
 47. Thecompound of claim 46, wherein R is aryl.
 48. The compound of claim 46,wherein R is heterocyclyl.
 49. The compound of claim 46, wherein R is—C₃-C₈cycloalkyl.
 50. The compound of claim 46, wherein L is a bond,—CH₂—, —C(O)—, —C(O)NH—, or —S(O)₂NH—.
 51. The compound of claim 50,wherein L is a bond.
 52. The compound of claim 50, wherein L is —CH₂—.53. The compound of claim 50, wherein L is —C(O)—.
 54. The compound ofclaim 50, wherein L is —C(O)NH—.
 55. The compound of claim 50, wherein Lis —S(O)₂NH—.